Electric field broadening of the 1A1(2) transition in azulene

Abstract
The change in the dipole moment of azulene upon excitation from the ground to the second excited state is deduced from electric field broadening experiments. A detailed study of the 0–0 band of this transition in a rigid solution of 3‐methylpentane (3‐MP) using polarized light shows that the change in the dipole moment (Δμ) is 1.23±0.14 D and that the transition moment is parallel to this vector. This value is compared with the results of the Stark effect in mixed crystals and with molecular orbital calculations. A less detailed study has been performed on the vibrationally excited bands of this transition. In addition, calculations of the polarizabilities of the first two excited states of azulene are reported and compared with recent experimental results in mixed crystals.